The Boy Next Door is a popular song composed by Hugh Martin and Ralph Blane in 1944 for the MGM musical film Meet Me in St. Louis, where it was introduced by Judy Garland. The song is sometimes performed under the alternate title The Girl Next Door. Written as a gentle, wistful ballad in waltz time, the composition features a flowing, lyrical melody that conveys romantic longing through its dreamlike rhythmic sway and simple, heartfelt harmonic language. The 32-bar AB form supports the song's narrative directness, with smooth phrasing designed to reveal character emotion in its original film context. Garland first recorded it for Decca Records on April 20, 1944, and the song quickly entered the broader popular repertoire. It became a widely performed standard of the Great American Songbook, attracting interpretations across pop, jazz, and vocal genres. Notable recordings include versions by Frank Sinatra on Songs for Young Lovers in 1954, Sarah Vaughan on Sassy in 1956, and Bill Evans on At Shelly's Manne-Hole in 1963, among many others. Jazz musicians have frequently adapted the tune as an improvisation vehicle, with arrangements appearing in real book collections. The composition exemplifies the golden age of Hollywood songwriting, blending accessible melody with emotional depth in a form that has proven remarkably durable across decades and musical styles.